<!DOCTYPE html>
<html>

<head>
    <meta charset="utf-8">
    <title>控制文本中的字母</title>
    <style>
        p.uppercase {
            text-transform: uppercase;
        }

        p.lowercase {
            text-transform: lowercase;
        }

        p.capitalize {
            text-transform: capitalize;
        }
    </style>
</head>

<body>
    <p class="uppercase">This is some text.</p>
    <p class="lowercase">This is some text.</p>
    <p class="capitalize">This is some text.</p>
</body>

</html>